Center cut shear



June 1, 1948. F. L. McGARY' ETAL CENTER CUT SHEAR Filed Oct. 3, 1944Patented June 1, 1948 NITED STATES. PATENT OFFICE CENTER CUT SHEARFrancis L. McGary and Charles E. McGary, Hardinsbm'g, Ky.

Application October 3, 1944, Serial No. 556,967

11 Claims. 1

The invention relates to a center cut shear, of the type used in cuttingsheet rnetal, and it is an object of the invention to provide animplement by means of which it is made possible to v punch. a hole in asheet of metal and then cut in any direction desired, with any desiredchanges in direction of cut, or to cut off down spouting. to cut offsheet metal pipe of all types and in any shape, and in general toprovide a shear of great versatility as compared with shears such ashere- Another object is to provide a shear that is particularly suitedto enter the wall of a building constructed of sheet metal, and to makeincisions therein, as for Windows and the like.

Referring now to the drawings, which are made a part of this applicationand in which similar parts are indicated by similar referencecharacters:

Fig. 1 is a side elevation of a preferred form of the invention, 7

Fig. 2, a top plan of the same, and

Fig. 3, a bottom plan.

In the drawings, reference character Ill indicates a shear member havingparallel cutting edges at its forward end and having at opposite sidesthereof blades II I I coacting with said cutting edges. said bladesbeing pivoted to the handle I!) at I2. The blades II, II are turnedupward at the rear of the pivot I2 and a handle I3 is pivotallyconnected to them at I4. A link 45. pivotally connected at IE to theupper handle and at I? to the lower one, serves to provide a sort oftoggle-like action for the operation of the shear.

The upper side edges of theforward portion of shear member ID atopposite sides of its flat upper face are formed as cutting edges I8,I8, as above stated, to coact with the corresponding inner edges of therespective shear blades H, II. the under faces of the blades beinginclined upwardly toward their outward edges, as shown in Fig. 1. At theunder side of the forward portion of the member Ill there are formedoppositely inclined faces I9 so that the end part is approximatelyV-shaped in section, and the said end tapers gradually to a point at l9,Preferably the angle formed by each face I9 with the adjacent fiat sideface of the blade grows steeper toward the point I9, the three facesthus forming an elongated taperedpoint.

This sharp point enables the user to stab the end of the tool throughsheet metal and the like. A narrow strip is cut out of the sheet betweenthe blades I I, II, and this aids in cutting in other than straightlines through a piece of work, since this strip can readily be bent outof the way of the blades, so that almost any desired shapes can be cutout of metal sheets, sheet metal spouting, and the like.

At the grip end of handle I3 the handgrip portion is bent to the left(looking backward along the tool in Fig. 2 from the point I9) away fromthe median plane passing through the two handies and perpendicular totheir pivots, and then is bent back again so that the extreme outercorner. as at 2|, lies approximately in the same plane as the righthandface of the main or body portion of said handle and the grip portionlies I mainly at the left of the median plane in Fig, 2. The gripportion is also twisted so as to turn the same about the aixs of saidhandle and to throw the bottom member 22 of the rip outward withrelation to the upper member 23, thereby to accommodate the grip mosteffectively to the thumb of the user.

The grip portion of the handle Ill is also offset laterally with respectto its body portion, and is bowed outwardly so that substantially all ofthe parts 24, 2 5 lies at the right of the median line or plane of theshear in Fig. 2 and, in fact, at the right of a plane passing throughthe righthand face of the bodyportion of the handle I0. Preferably aswell is provided at 25 on the working faceof grip member 25 to fit thefingers, and a hole 21 is provided in advance of the main fingeropening, whereby the forefinger of the user may fit conveniently andcomfortably into said hole. This opening for the forefinger is useful inproviding convenient means for control of the shear, when the hand isrelaxed, as in pushing the shear forward after a stroke to locate it foranother stroke, and for other like operations. The hole is formed in orjust back of the straight portion of the handle. In some shears theforefinger lies in front of the grip since the finger hole is too smallto contain all of the fingers, and when in that location is convenientlyemployed for pulling the shear back from the work, but not for pushingthe shear forward toward the work to take another bite.

By reason of the offset arrangement of the grip portions of the toolhandles the working surfaces of the grip portions are caused to lie inproper relation to those areas of the fingers and thumb where thegreatest application of force naturally falls, and therefore the toolcan be used with maximum effectiveness and with minimum exertion on thepart of the user. The arrangement of the rocking link, with the pivot ofthe link close to that of the handle and the movable blades I l, l I,and so located that the line through-points '4, I6 and H straightens asthe tool closes, also makes for easy and efiective operation of thetool. It will be obvious to those skilled in the ar that many changesmay be made in the device,

handle pivoted to the blades of .said pair above and. rearwardly of saidpivot, a link .pivoted to .said second-named handle rearwardly ofitspivotal connection to said blades, and a pivot .for

. .said .link onsaidfirst-named handle rearwardly of.-and below itspivot on .thelsecond-named handie. 2. A shear comprising a blade, ahandle rigid therewith, a. blade :pivoted to said handle, ahandlepivoted to the second-named blade above and rearwardly ofthepivotal connection of the v.lelade to the first-named handle, and alink connecting said handles,.said link being pivoted to thesecond-named handle rearwardly from. the, pivotal connection between thehandle and said second-named blade and bein pivoted to the first-namedhandle rearwardly of and belowits pivot'to thesecond handle.

3. A shear having a blade provided with flat parallellside ,faces, andav flat upper face, said blade also. havinginclined flatfacesintersecting the upper fiat face to provide therewith a tapering point,said inclined faces meeting at the bottom oflthe blade to form a cuttingedge'gradually increasing in. obtnseness and .in distance from said.flat upper face, and a blade coacting with the first-named blade.

4. A shear as in.,.claim 3, the front end of said fiatface being V-.shaped, and coacting blades at opposite sides of the first-namedblade,said coacting blades terminating. approximately at the base ofsaidV-shaped portion.

5. A shearcomprising abladehaving a flat upper. face at its iorwardendwith the cutting edges at the sides of saidface, and having oppositelybeveled flat faces belowsaid .cutting edges,

.the bevels. on said'facesmeeting at the bottomof the jaw to form acutting edge and the jaw tapering to a .point,,said jawbeing triangularin secti-on and increasing progressively in depth back of said point toform a cuttingedgecoacting .with

the first-named cutting edges, so that the for- V ,ward, ends of theside jaws can coact with the firstnamed jaws in punching a hole insheetmetal or the'like.

8..IA device as in claim 5, including auxiliary blades at opposite sidesof the first-named blade, the auxiliary blades terminating at theforward end-of the side cutting edges of the first-named blade, andtapering toward said blade at their forward ends, so as to coact withthe point thereo't'in punching a hole. '9. A. shear as in claim 5,including a blade at each. side of the first-named blade, the second-.narned blades being pivoted to the first-named bladerearwardly of therear end of its lower cutting. edgev and terminating. at the forward endof the first-named cutting edges, so that the for- ,upper face andoppositely beveled flat side faces,

the bevels of the blade merging at the underside of said blade to form acutting edge and meeting with said upper face at the end of the blade toform a pointed portion triangular in section extendingiorwardly from theend of said flat upper face.

11. A device as in, claim 10, including a coacting forwardly taperingbladeterminating at the rearend o'f saidpointed portion FRANCIS L.McGARY,

CHARLES E. McGARY.

REFERENCE S CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS .Number Name Date 25,508 Heinisch Sept. 20, 185973,255 Buell et a1. May 26, 1863 35,500 Witte Dec. 29, .1868 94,247Seymour Aug. 31, 1869 325,291 Warner Sept. 1, 1885 430,677 Pearsall June24, 1890 752,436 Boyd Feb. 16, 1904 760,204 Heinisch May 17, 1904968,219 Wheeler Aug. 23, 1910 1,357,200 Kiefer Oct. 25, 1920 1,436,603 MPhilbert -4 Nov. 21, 1922 2,006,926 Lincoln July 2, 1935 2,207,222McGary July 9, 1940

